Disposable aerosol generator system and methods for administering the aerosol

ABSTRACT

A disposable aerosol generator for use with an inhaler device which includes a heater adapted to volatilize fluid stored in the disposable aerosol generator and method of using the inhaler. The disposable body includes a sealed chamber and an outlet, the chamber being located between first and second layers of material. The chamber holds a predetermined volume of a fluid which is expelled through the outlet when the fluid in the chamber is volatilized by the heater. The disposable body can include a series of spaced apart aerosol generators, each of which can be advanced to a release position at which the heater can heat one of the fluid containing chambers. Prior to heating the fluid, the outlet can be formed by severing the first and/or second layer with a piercing element and the volatilized fluid can be expelled from the outlet into a passage of a dispensing member.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to an apparatus, system and methods ofadministering a fluid such as a medicated fluid in metered amount suchas a unit dose to treat respiratory ailments. In particular, theinvention relates to disposable aerosol generators, wherein the aerosolsare generated via vaporization.

2. Description of Related Art

Aerosols are useful in a variety of applications including treatment ofrespiratory ailments. Various techniques for generating aerosols aredisclosed in U.S. Pat. Nos. 4,811,731; 4,627,432; 5,743,251; and5,823,178.

In particular, two distinct methods for delivery of medicated fluid inthe form of an aerosol have been developed. In accordance with onemethod, a pharmaceutically active drug is dispensed in a low boilingpoint propellant (e.g., chloro-fluoro-carbon (CFC) or (HFA)) loaded in apressurized canister from which the drug/propellant formulation may bereleased by the use of a device generally known as a metered doseinhaler. Once released the propellant evaporates and particles of thedrug are inhaled by the patient. The other method involves the use of anebulizer which creates an inhalable mist of fine particles from asolution or suspension of a drug. Both methods are hindered bysignificant problems relating to administering the proper dose.

In drug delivery applications, it is typically desirable to provide anaerosol having average mass median particles diameter of less than 2microns to facilitate deep lung penetration. Additionally, it isdesirable, in certain drug applications, to deliver medicaments at highflow rates (i.e., above 1 milligram per second). Devices for controllingthe flow rate of an aerosol are known. For example, U.S. Pat. No.4,790,305 concerns controlling the particle size of a metered dose ofaerosol for delivery to the walls of bronchi and bronchioles by fillinga first chamber with medication and a second chamber with air such thatall of the air is inhaled prior to the inhaling of medication, and usingflow control orifices to control the flow rate. U.S. Pat. No. 4,926,852relates to metering a dose of medication into a flow-through chamberthat has orifices to limit the flow rate to control particle size. U.S.Pat. No. 3,658,059 discloses a baffle that changes the size of anaperture in the passage of the suspension being inhaled to select thequantity and size of particles delivered. A problem associated withthese devices is that they process the aerosol after it is generated andare inefficient and wasteful.

To meet the requirements of administering a fluid in the form of anaerosol and to overcome the disadvantages of the prior art, it is anobject of the present invention to provide an aerosol generator whichvaporizes the fluid at a controlled flow rate regardless of the fluid'sviscosity.

It is another object of the invention to obtain uniform vaporization ofthe fluid that is expelled from the aerosol generator.

It is a further object of the invention to provide a disposable aerosolgenerator which can deliver a metered dose of the fluid. By deliveringindividual single doses of medicated fluid it is possible to avoidcontamination of the fluid, thereby negating the need for bacteriostaticcompounds within the drug formulation.

It is yet another object of the invention to provide a disposablecartridge which can incorporate a package having therein multipledisposable aerosol generators, each of which provides a single shotdelivery, as required by the user.

Other objects and aspects of the present invention will become apparentto one of ordinary skill in the art upon review of the specification,drawings and claims appended hereto.

SUMMARY OF THE INVENTION

According to one aspect of the invention, a disposable aerosol generatoris provided which is adapted for use with an inhaler device whichincludes a heater arranged to volatilize fluid stored in the disposableaerosol generator. The aerosol generator comprises a disposable bodyhaving a sealed chamber and an outlet wherein first and second layers ofmaterial define the chamber. The chamber accommodates a predeterminedvolume of a fluid which is expelled through the outlet when the fluid inthe chamber is volatilized by the heater.

According to another aspect of the invention, an inhaler device isprovided which is usable with the disposable aerosol generator mentionedabove, the inhaler device including a heater arranged to heat the fluidin the chamber so as to expel volatilized fluid from the outlet. Theheater can comprise a layer of resistance heating material on asubstrate which includes an opening located adjacent the outlet. Inorder to form the outlet, an opening device such as a piercing elementcan be provided which is adapted to pierce the first and/or second layerto form the outlet.

According to a further aspect of the invention, a method of using theinhaler device mentioned above is provided, the method includingsevering the first and/or second layer so as to form the outlet andactivating the heater so as to volatilize the fluid in the chamber andexpel the volatilized fluid through the outlet. According to a preferredmethod, the disposable body includes a series of spaced apart aerosolgenerators and the method includes moving the disposable body relativeto the inhaler device so as to locate a first one of the aerosolgenerators at a position where the heater can heat the fluid in thechamber of the first aerosol generator and volatilize the fluid therein.The severing can be carried out by driving a piercing member through thefirst and/or second layer and the outlet can be located adjacent apassage of a dispensing member such that the volatilized fluid formed bythe heater is expelled into the passage after passing through theoutlet.

BRIEF DESCRIPTION OF THE DRAWINGS

The objects and advantages of the invention will become apparent fromthe following detailed description of the preferred embodiments thereofin connection with the accompanying drawing, in which:

FIGS. 1 and 2 show details of a disposable body containing a series ofaerosol generators according to one embodiment of the invention, FIG. 1showing a top view thereof and FIG. 2 showing a side view thereof;

FIG. 3 shows an inhaler device according to an embodiment of theinvention;

FIG. 4 shows details of a heater of the inhaler device shown in FIG. 3;

FIG. 5 shows details of a first heater element pattern which can be usedfor a resistance heating layer of the heater shown in FIG. 4; and

FIG. 6 shows details of a second heater element pattern which can beused for a resistance heating layer of the heater shown in FIG. 4.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS OF THE INVENTION

The present invention provides an inhaler effective for administering afluid such as a medicated fluid in aerosol form. It has surprisingly andunexpectedly been determined that a metered amount of fluid can bedelivered from the inhaler via a disposable aerosol generator whereinthe fluid is fully vaporized and delivered at a predetermined flow rate.

With reference to FIGS. 1 and 2, an aerosol generator in accordance withone embodiment of the present invention is shown schematically. A singleshot chamber or reservoir 10 is designed to accommodate a predeterminedvolume of fluid which can incorporate a medicament for treating variousrespiratory ailments (e.g., a partial list includes albuterol,isoproterenol sulfate, metaproterenol sulfate, terbutaline sulfate,pirbuterol acetate, salmeterol xinotoate, formotorol; steroids includingbeclomethasone dipropionate, flunisolide, fluticasone, budesonide andtriamcinolone acetonide, beclomethasone dipropionate, triameinoloneacetonide, flunisolide and fluticasone, etc.). Of course, the volume andcomposition of fluid may be predicated on the amount desired to treat aparticular medical ailment.

An outlet 20 is in fluid communication with the chamber 10 and a heatingmember (not shown) disposed on or in proximate location to eitherchamber 10 and/or outlet 20 is operable to vaporize the fluid in thechamber 10 and eject the vaporized fluid out of the outlet 20. Forinstance, a heating member may be employed in conjunction with both thechamber 10 and outlet 20. In a preferred embodiment, the heatercomprises part of a reusable inhaler device. However, the heater can beincorporated in the disposable body, e.g., a resistance heating elementheated by passing current therethrough or by inductively heating theheating element.

In accordance with a preferred embodiment of the invention, chamber 10is constructed from a material (e.g., polymeric, aluminum foil)resistant to heating. For example, in the embodiment shown in FIGS. 1and 2, the chamber 10 is formed as a recess 12 in an injection moldedbody 14 of polymer material and a flow passage 30 comprises a channel 16in the body 14, the channel 16 extending from the recess 12. The chamber10 is sealed by a layer 18 such as aluminum foil heat sealed to the body14.

In order to provide multiple doses of medicated fluid in a disposablepart of an inhaler, the body 14 can include a plurality of recesses 12.The laminate thus described is capable of withstanding the pressureapplied to the interior of the chamber through the application of heatnecessary to vaporize the fluid contained therein. Outlet 20 ispreferably a small aperture at the end of the flow passage 30, theoutlet being initially closed to the atmosphere. The flow passage 30 canhave any suitable size which is effective to expel the vaporized fluidinto the atmosphere and form the aerosol of desired particle size. Forinstance, flow passage 30 can have an inside diameter of about 0.05 toabout 0.60 millimeter, preferably about 0.2 mm and a length of about 100to 200 times the inside diameter. The chamber 10 can have any desiredsize such as a size suitable to deliver a single dose of medicatedfluid, e.g., 5 μl.

In operation, the fluid in the chamber 10 is heated by a heating devicewhich heats the fluid to a temperature sufficient to volatilize thefluid. In the case of an organic liquid material, the heating devicepreferably heats the fluid to approximately the boiling point, andpreferably does not heat the fluid above 400° C., as most organic fluidsare not stable when they are exposed to temperatures above 400° C.

Heating can be achieved in various ways including resistance orinduction heating to heat the fluid via thermal conduction. Suitableheating devices envisioned for employment in the aerosol generator ofthe present invention include electrical resistance heaters, depositedresistance heating material such as thin platinum layers,electro-induction heating coils, etc. For example, the heating devicecan comprise an electrical resistance heater element arranged tothermally conduct heat into the chamber 10. The heater can be anysuitable material such as platinum, tungsten, molybdenum or metal alloysuch as an iron-based alloy having 71.7% (by weight) iron, 23% chromium,and 5.3% aluminum.

The flow passage 30 can have any desired configuration. For instance,the flow passage can have a uniform cross-sectional area along thelength thereof between the chamber 10 and the outlet 20. However, theflow passage can vary in size along the length thereof, e.g., tapered soas to become more narrow in a direction towards the outlet 20. Further,the chamber need not comprise a concave circular recess, but rather cancomprise any desired configuration sized to accommodate a single dose ofthe medicated fluid.

According to a preferred embodiment, the heater device can comprise alayer of resistance heating material deposited on the outside of asupport member such as a plastic or ceramic member, e.g., alumina,glass, titania, zirconia, or yttria-stabilized zirconia which does notexperience oxidation at normal operating temperatures.

The heater support and the heater layer preferably have a roughlymatching coefficient of thermal expansion to minimize thermally induceddelamination. Also, the ceramic support material can have a surfaceroughness to improve adhesion of the deposited heater layer. Platinum isdesirable as a heater material in that it is resistant to oxidationdegradation or other corrosion.

The heater layer can be deposited as a thin film on a ceramic supportsuch that the heater layer has a thickness of, e.g., less thanapproximately 2 μm. The heater layer can be deposited onto the ceramicby any suitable method such as DC magnetron sputter deposition, e.g.,using an HRC magnetron sputter deposition unit, in argon at 8.0×10⁻³Torr. Alternatively, other conventional techniques such as vacuumevaporation, chemical deposition, electroless plating, electroplating,and chemical vapor deposition can be employed to apply the heater layerto the substrate. It will be appreciated by those skilled in the art,that the energy produced by the heating device can be distributedoptimally by tailoring the pattern of the thin film. For example, theheater pattern can be arranged to provide more heat near the outlet 20than in the vicinity of the recess 12.

The closed end of the flow passage 20 can be opened by an opening devicesuch as solenoid activated puncturing element. Alternatively, a cuttingblade or scissors suitable for cutting the material sealing the flowpassage 30 can be used to expel the volatilized fluid. It is furtherwithin the scope of the invention that other techniques such as abreakable seal can be employed on the closed end of the flow passage.The volatilized fluid can be expelled in a controlled manner taking intoaccount properties of the fluid and the amount of heat needed tovaporize the fluid. The volatilized fluid can be expelled from theoutlet 20 at a high velocity, e.g., approximately 90 m/s, but thevolatilized fluid can be quickly dissipated in the atmosphere as theaerosol is formed from the condensing vapor, e.g., within about 2 mm ofthe outlet 20. The volatilized fluid can be mixed with ambient air in aninhaler mouthpiece surrounding the outlet 20, whereupon rapid coolingand condensation of the vapor result in formation of the aerosol.

The characteristics of the aerosol generated in accordance with theinvention is a function of various parameters of the generator and thefluid provided. For aerosols intended for inhalation, for example, it isdesirable for the aerosol to be approximately at body temperature wheninhaled and for the mass media particles of the aerosol to be less than2 microns, preferably between 0.5 and 1 micron.

Upon delivery of the metered amount of fluid, in aerosol form, theaerosol generator comprising the chamber 10, outlet 20 and flow passage30 can be discarded. In the case where multiple generators are providedin a multidose cartridge such as the disposable body shown in FIGS. 1and 2, the cartridge can be disposed of when the last of the individualchambers have been emptied.

In accordance with another preferred embodiment, the heating device cancomprise a plurality of heating members arranged to heat the fluid inthe chamber and/or along the flow passage. Also, the fluid in thechamber could be expelled mechanically, e.g., by a member which pushesthe fluid into the flow passage and a heater along the flow passage canbe used to volatilize the fluid and expel the vaporized fluid out of theoutlet 20.

With reference to FIGS. 3-6, a fluid delivery system is depicted,wherein individual disposable aerosol generators are transported to afluid release position as required by the user. The fluid deliverysystem 100 includes a cartridge 110 loaded with disposable aerosolgenerators 120. In a preferred embodiment, the aerosol generators 120are provided in the form of packets, preferably constructed as describedabove in connection with FIGS. 1 and 2. A heating device 130 providessufficient energy to each generator 120 to vaporize the fluid and expelthe vaporized fluid through a passage in a dispenser 140. An openingdevice 150 can comprise a puncture element 152 activated by a solenoid154, the puncture element 152 being operable by a suitable controllerand circuitry to penetrate the layer 18 in the vicinity of outlet 20.

The heating device 130 includes an electrically resistive heatingelement 132 on a substrate 134, the heating element 132 being powered byelectrically conductive connections 136 extending through vias in thesubstrate 134. The substrate 134 includes an opening 138 through whichthe piercing end of the puncture element 152 can move towards and awayfrom the cartridge 110. In operation, the controller can be activated tooperate the system 100 so as to rotate the cartridge 110 to a drugrelease position, actuate the solenoid to drive the puncture arm towardsthe cartridge so as to pierce the channel 16 and thereby form the outlet20, and activate the heating element so as to heat the fluid in thechamber 10 whereby vaporized fluid is expelled through the dispenser140.

FIGS. 5 and 6 show embodiments of different heater patterns for theheater 130. The heater 130 a shown in FIG. 5 includes a heating element132 a configured to completely cover the chamber 10 and flow passage 30.With the heater element pattern shown in FIG. 5, greater heating can beachieved in the flow passage 30 due to the smaller cross sectional areaof the heating element along the flow passage. The heater 132 b shown inFIG. 6 includes a heating element 132 b configured as a sinusoidallyshaped strip which overlies chamber 10 and a rectilinear strip whichoverlies the flow passage 20.

In operation, the disposable cartridge 110 can be loaded into theinhaler 100, and a transport mechanism (not shown) can be operated tosuccessively transport the aerosol generators to the release position atwhich the heater volatilizes the fluid contained in the respectivechamber. Driving power for the transport mechanism, the solenoid and theheating element can be provided by a power source such as a 9-voltbattery. The dispenser 140 can be arranged to supply the vaporized fluidto a mouthpiece (not shown) of the inhaler 100.

While the invention has been described in detail with reference tospecific embodiments thereof, it will be apparent to those skilled inthe art that various changes and modifications can be made, andequivalents employed, without departing from the scope of the appendedclaims.

What is claimed is:
 1. A disposable aerosol generator for use with aninhaler device which includes a heater adapted to volatilize fluidstored in the disposable aerosol generator, comprising: a disposablebody including first and second layers of material and a series ofspaced apart aerosol generators, each of the aerosol generatorsincluding a flow passage extending between a sealed chamber and anoutlet which can be opened to expel volatilized fluid, the flow passageof each aerosol generator being located between the first and secondlayers, the disposable body being configured to fit in the inhalerdevice to allow advancement of each respective aerosol generator to arelease position at which the fluid in the chamber of the respectiveaerosol generator can be heated, the chamber of each aerosol generatoraccommodating a predetermined volume of a fluid which is expelled as thevolatilized fluid through the opened outlet when the fluid in thechamber is volatilized.
 2. An inhaler device usable with the disposableaerosol generator according to claim 1, wherein the inhaler deviceincludes a heater arranged to heat the fluid in the chamber of eachrespective aerosol generator or a respective one of the aerosolgenerators so as to expel volatilized fluid from the opened outlet. 3.The inhaler device according to claim 2, wherein the heater comprises anelectrical resistance heater.
 4. The inhaler device according to claim3, wherein the heater comprises a layer of resistance heating materialon a substrate, the substrate including an opening located adjacent theoutlet of each respective aerosol generator or a respective one of theaerosol generators.
 5. The inhaler device according to claim 2, furthercomprising an opening device, the opening device being adapted to piercethe first layer and/or second layer and open the outlet of eachrespective aerosol generator or a respective one of the aerosolgenerators.
 6. The inhaler device according to claim 5, wherein theopening device includes a solenoid activated piercing element, thepiercing element including a movable tip which is located in the openingin the substrate, the tip being moved upon actuation of the piercingelement such that the tip penetrates the first layer of the disposablebody.
 7. The inhaler device according to claim 2, wherein the disposablebody is movably supported such that the chamber of each respectiveaerosol generator or a respective one of the aerosol generators can bemoved to a release position at which the heater can heat the fluid inthe respective chamber sufficiently to volatilize the fluid to expel thevolatilized fluid through the opened outlet.
 8. The inhaler deviceaccording to claim 4, wherein the layer of resistance heating materialcomprises a strip arranged in a pattern which is coextensive with thesize of the chamber.
 9. The inhaler device according to claim 3, furthercomprising a dispensing member located adjacent the outlet of eachrespective aerosol generator or a respective one of the aerosolgenerators, the volatilized fluid expelled from the opened outletpassing through a passage in the dispensing member.
 10. The inhalerdevice according to claim 2, wherein the first layer comprises a layerof polymer material and the second layer of material comprises a foilheat sealed to the polymer layer, the inhaler device including anopening member which is operable to pierce the foil layer to open theoutlet of each respective aerosol generator or a respective one of theaerosol generators immediately prior to when the heater is activated tovolatilize the fluid in the chamber of the respective aerosol generator.11. The inhaler device according to claim 8, wherein the disposable bodyincludes a flow passage extending rectilinearly from the chamber of eachof the aerosol generators, the heater including a first portion arrangedto heat the chamber and a second portion arranged to heat the flowpassage of each respective aerosol generator or a respective one of theaerosol generators, the first and second portions of the heatercomprising a layer of resistance heating material configured such thatthe second portion of the heater becomes hotter than the first portionof the heater during actuation of the heater to volatilize the fluid inthe chamber of the respective aerosol generator.
 12. A method of formingan aerosol using the inhaler device according to claim 3, comprisingsevering the first and/or second layer so as to open the outlet of eachrespective aerosol generator or a respective one of the aerosolgenerators and activating the heater so as to volatilize the fluid inthe chamber and expel the volatilized fluid through the opened outlet ofthe respective aerosol generator.
 13. The method according to claim 12,wherein the method comprises moving the disposable body relative to theinhaler device so as to locate a first one of the aerosol generators ata position where the heater can heat the fluid in the chamber of thefirst aerosol generator and volatilize the fluid therein.
 14. The methodaccording to claim 12, wherein the severing is carried out by driving apiercing member through the first and/or second layer, the outlet ofeach respective aerosol generator or a respective one of the aerosolgenerators being located adjacent a passage of a dispensing member andthe volatilized fluid formed by the heater being expelled into thepassage after passing through the opened outlet.
 15. The methodaccording to claim 14, wherein the disposable body includes a flowpassage extending rectilinearly from the chamber of each of the aerosolgenerators, the heater including a first portion arranged to heat thechamber of each respective aerosol generator or a respective one of theaerosol generators and a second portion arranged to heat the flowpassage of the respective aerosol generator, the first and secondportions of the heater comprising a layer of resistance heating materialconfigured such that the second portion of the heater becomes hotterthan the first portion of the heater during volatilization of the fluidin the chamber.
 16. The aerosol generator according to claim 4, whereineach of the chambers contains a predetermined volume of a fluidincluding at least one medicament selected from the group consisting ofalbuterol, isoproterenol sulfate, metaproterenol sulfate, terbutalinesulfate, pirbuterol acetate, salmeterol xinotoate, formotorol,beclomethasone dipropionate, flunisolide, fluticasone, budesonide,triamcinolone acetonide, beclomethasone dipropionate, triamcinoloneacetonide, flunisolide and fluticasone.
 17. The aerosol generatoraccording to claim 12, wherein the fluid includes at least onemedicament selected from the group consisting of albuterol,isoproterenol sulfate, metaproterenol sulfate, terbutaline sulfate,pirbuterol acetate, salmeterol xinotoate, formotorol, beclomethasonedipropionate, flunisolide, fluticasone, budesonide, triamcinoloneacetonide, beclomethasone dipropionate, triamcinolone acetonide,flunisolide and fluticasone.
 18. An inhaler device, comprising: adisposable aerosol generator comprising a disposable body including asealed chamber accommodating a fluid and a flow passage in communicationwith the chamber, the disposable body including first and second layersof material defining the chamber, the flow passage having an outletwhich can be opened to expel volatilized fluid and having a diameter offrom about 0.05 mm to about 0.60 mm; and a heater arranged to heat thefluid while in the chamber so as to expel volatilized fluid from theopened outlet.
 19. An inhaler device, comprising: a disposable aerosolgenerator comprising a disposable body including a sealed chamberaccommodating a fluid and a flow passage in communication with thechamber, the disposable body including first and second layers ofmaterial defining the chamber, the flow passage having an outlet whichcan be opened to expel volatilized fluid and having a width of fromabout 0.05 mm to about 0.60 mm; and a heater arranged to heat the fluidwhile in the chamber so as to expel volatilized fluid from the openedoutlet.
 20. The inhaler device according to claim 18, wherein thechamber contains a predetermined volume of a fluid including at leastone medicament selected from the group consisting of albuterol,isoproterenol sulfate, metaproterenol sulfate, terbutaline sulfate,pirbuterol acetate, salmeterol xinotoate, formotorol, beclomethasonedipropionate, flunisolide, fluticasone, budesonide, triamcinoloneacetonide, beclomethasone dipropionate, triamcinolone acetonide,flunisolide and fluticasone.
 21. The inhaler device according to claim19, wherein the chamber contains a predetermined volume of a fluidincluding at least one medicament selected from the group consisting ofalbuterol, isoproterenol sulfate, metaproterenol sulfate, terbutalinesulfate, pirbuterol acetate, salmeterol xinotoate, formotorol,beclomethasone dipropionate, flunisolide, fluticasone, budesonide,triamcinolone acetonide, beclomethasone dipropionate, triamcinoloneacetonide, flunisolide and fluticasone.